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Lewy Body Dementia

September 3, 2019

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Quiz
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The Los Angeles Theatre honors Robin Williams (1951-2014) on their marqueePhoto credit: This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Lewy body dementia (LBD, sometimes referred to as Lewy body disorder) is an umbrella term that includes Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB), two dementias characterized by abnormal deposits of the protein alpha-synuclein in the 1) ___. Five years ago, Robin Williams, a beloved comedian and serious actor, committed suicide. During his autopsy, Lewy bodies were found in his brain. In addition, reports are that he also suffered from Parkinson's 2) ___. Since his death, there has been a growing interest in Lewy body dementia referred to as LBD, and some suggest his suicide was caused by his disease(s).

In general, there are two main types of LBD; doctors and researchers use the “one year rule“ to diagnose LBD; if cognitive symptoms appear within a year of movement problems, the diagnosis is dementia with Lewy 3) ___, but if cognitive problems develop more than a year after the onset of movement problems, the diagnosis is Parkinson's disease dementia. These diagnoses are usually made by a neurologist. LBD disease is also termed dementia with Lewy bodies (DLB) in the medical literature. LBD is a progressive and degenerative disease of the brain caused by the presence of Lewy bodies, abnormal proteins that disrupt communication among brain 4) ___. Lewy bodies were first noted in autopsy brains from patients with Parkinson's disease in 1914 by Frederick Lewy. LBD is a progressive disease so identifiable stages are not present; however, there has been mention in the literature of “early-stage“ and “late stage“ symptoms.

The cause of LBD is not known, but the condition is related to an abnormal protein in the brain, termed alpha-synuclein, that makes up the Lewy bodies. The findings from 5) ___ studies suggest about 10% to 20% of individuals with dementia have LBD. This disease is described in all races and is slightly more common in men; it may begin in late middle age (50 years old) or most often in the elderly. As previously mentioned, is often closely associated with Parkinson's disease dementia. Symptoms of LBD can fluctuate but usually become progressively worse over time. Early in the disease, fluctuations between normal and abnormal behavior, mood, and cognitive ability can occur. The central feature of this disease is progressive dementia shown by deficits in attention and minor dysfunctions in the early stages that can progress to severe 6) ___. In severe dementia, the person's inability to carry out normal daily functions, loss of recognition of family members, and other severe cognitive, behavior and mood problems can render the individual virtually helpless. Other features include fluctuating cognition, visual hallucinations, and spontaneous features of Parkinsonism such as body stiffness, tremors, shuffling gait, emotionless facial features and/or decreased coordination.

The diagnosis is made on the basis of symptoms and their time of occurrence in patients. However, most doctors that make the diagnosis (neurologists) also typically use other tests primarily to rule out other causes for the symptoms. There are no sensitive or specific blood or urine tests that 7) ___ LBD. However, routine laboratory tests such as a basic metabolic panel, CBC, thyroid studies, vitamin B12 levels; and tests for syphilis, Lyme disease, or HIV also may be ordered. MRI, CT scans, and other studies of the brain are used to help distinguish LBD from other problems that have similar symptoms. Currently there is no evidence that any medications can decrease rate of LBD cognitive decline. However, the following medications are often used in patients who have LBD:

1.     cholinesterase inhibitors,

2.     second-generation antipsychotics,

3.     antidepressants,

4.     benzodiazepines, and

5.     dopamine precursors.

Unfortunately, LBD is a progressive disease (usually over years), although the rate of progression varies. In general, the lifespan of patients diagnosed with LBD varies from about 5 to 8 years. Patients die from multiple complications (immobility, falls, poor nutrition, swallowing difficulties, or pneumonia). The prognosis of LBD over time is fair to poor. LBD is a difficult disease for the patient and the patient's loved ones and caregivers to manage because of its unpredictable exacerbations and continual progression. This disease robs patients of their body and brain functions, sometimes slowly, other times more rapidly. It is difficult for patients and their caregivers to deal with an ever-increasing decline in function; most patients may require daily care, home health, or institutionalization as their disease progresses.

The synucleinopathies (DLB, PDD, and Parkinson's disease) have shared features of parkinsonism, impaired cognition, sleep disorders, and visual hallucinations. A core feature is REM sleep behavior disorder (RBD), in which individuals lose normal muscle paralysis during REM sleep, and act out their dreams. Other frequent symptoms include visual 8) ___; marked fluctuations in attention or alertness; and slowness of movement, trouble walking, or rigidity. The autonomic nervous system is usually affected, and can result in symptoms such as changes in blood pressure, heart and gastrointestinal function, urinary incontinence, and constipation. Mood changes such as depression, apathy, and anxiety are common. RBD may appear decades before any other symptoms. On autopsy, 94 to 98% of individuals with polysomnography-confirmed RBD are found to have a synucleinopathy - most commonly DLB or Parkinson's disease, in about equal proportions. Other symptoms of the specific synucleinopathy usually manifest within 15 years of the diagnosis of RBD, but may emerge up to 50 years after RBD diagnosis.

While both dementia with Lewy bodies and Parkinson's disease dementia have similar neuropathologic features, they are highly variable and should not be distinguished on pathologic features alone. Generally, DLB is distinguished from PDD by the time frame in which dementia symptoms appear relative to parkinsonian symptoms. DLB is diagnosed when cognitive symptoms begin before or at the same time as parkinsonism, while PDD is the diagnosis when Parkinson's disease is well established before the dementia occurs. Dementia with Lewy bodies and Parkinson's disease dementia are similar in many ways, suggesting there may be a common pathophysiological mechanism, with PDD and DLB at opposite ends of an LBD spectrum, and a shared component of protein deposits in Lewy bodies and Lewy neurites. Lewy bodies and Lewy neurites have been found to develop from aggregation of misfolded alpha-synuclein, a protein thought to assist in neurotransmitter release and vesicle turnover. However, no definitive link between Lewy bodies and neurodegenerative effects has been found. Despite differences in the timing of the appearance of symptoms, the two dementias “show remarkably convergent neuropathological changes at autopsy“. Current disease management focuses on treating each symptom. For cognitive symptoms, the standard treatment is Cholinesterase Inhibitors (CHEIs). This drug class is effective in reducing apathy, visual hallucinations, and delusions symptoms. For movement symptoms, Levodopa is considered the standard treatment. Some research efforts in exploring alternative LBD therapeutics have been called questionable due to a variety of factors including choice of study design, exclusion criteria, limitation of outcomes, strength of evidence, and complications between PDD and DLB classifications.

Beside pharmacological management, there are other available non-medical treatments like physical therapy, speech therapy, occupational therapy, individual and family psychotherapy, and support groups that might be recommended by physicians to improve and address the needs of each patient. As of 2013, Lewy body dementias affect about 1.3 million people in the United States, though this number is said to be an underestimate given the difficulty of diagnosing the disorder. LBD usually develops after the age of 50. While a study published on JAMA Neurology in 2013 pointed out a notable difference between DLB and PDD in age and gender, more research is needed to confirm any discrepancies.

Lewy body dementias are more often misdiagnosed than any other common dementia. Most people with DLB had not heard of the condition prior to diagnosis; general awareness about LBD lags well behind that of Parkinson's and Alzheimer's diseases, even though LBD is the second most common dementia, after 9) ___. It is frustrating for families and caregivers to find that few people, including many healthcare professionals, are knowledgeable about LBD. Lack of knowledge can have significant health consequences because people with LBD have severe sensitivity to 10) ___ often used to treat the symptoms. The Lewy Body Dementia Association (LBDA) and the Lewy Body Society promote awareness and provide support that helps society, by reducing costly use of healthcare, and families with LBD, by reducing stress. These organizations, and others in Argentina, Australia and Japan, help raise knowledge and help families with LBD become advocates to raise awareness about the disease. Sources: MedicineNet.com; Wikipedia

ANSWERS: 1) brain; 2) disease; 3) bodies; 4) cells; 5) autopsy; 6) dementia; 7) diagnose; 8) hallucinations; 9) Alzheimer's; 10) antipsychotic

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